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Abstract:

Provided are a tooth model having parts corresponding to tartar formed
uniformly and a method of manufacturing the tooth model. A tooth model
(10) used for dental training comprises a main body having a tooth crown
(11) molded to look like the shape of a tooth and a tooth root (12), and
protrusions (13) seamlessly formed on the surface of the main body, and
the main body and the protrusions (13) are composed of the same material.
The protrusions (13) and the main body of the tooth model (10) can be
integrally molded. Therefore, the repeated use of the common molding die
allows the parts corresponding to tartar to be formed uniformly.

Claims:

1. A tooth model used for a dental training, the tooth model comprising:
a main body that is formed in imitation of a form of a tooth and
comprises a tooth crown and a tooth root; and a protrusion protruding
from a surface of the main body seamlessly, wherein the main body and the
protrusion are made of the same material.

2. The tooth model according to claim 1, wherein the protrusion has a
size of 0.3 mm to 0.7 mm, both ends inclusive, in a plan view.

3. The tooth model according to claim 1, wherein the protrusion comprises
an edge portion on a tooth root side of the protrusion having a form
expanded toward the tooth root side in a plan view.

4. The tooth model according to claim 3, wherein the protrusion comprises
an edge portion on the tooth root side having a partial form of a
circular arc or elliptical circular arc in a plan view.

5. The tooth model according to claim 1, wherein the protrusion has a
maximum height of 0.15 mm to 0.35 mm, both ends inclusive.

6. The tooth model according to claim 1, wherein the protrusion has a
form having no sharp-angle corner in a cross-sectional view that is
perpendicular to a tooth axis of the tooth model.

7. The tooth model according to claim 6, wherein the protrusion comprises
a partial form of a circular arc or elliptical circular arc in a
cross-sectional view that is perpendicular to the tooth axis.

8. The tooth model according to claim 1, wherein the material provides a
Brinell hardness of 20 to 30, both ends inclusive, and provides a
flexural strength of 700 kgf/cm2 to 1000 kgf/cm2, both ends
inclusive.

9. The tooth model according to claim 1, wherein the dental training is
that for removing tartar.

10. A method of producing a tooth model used for a dental training, the
method that uses an elastically deformable molding die comprising a
concave part formed substantially symmetrically to a form of the tooth
model, with the concave part provided with a miniature dent on a surface
of the concave part and comprises the steps of: supplying the concave
part with a material fluid that is a raw material for the tooth model;
causing the material fluid to solidify in the concave part to form the
tooth model having a protrusion of a form substantially symmetrical to
the miniature dent on a surface of the tooth model; and extracting the
tooth model from the concave part.

Description:

TECHNICAL FIELD

[0001] The present invention relates to a tooth model for use in dental
trainings, and to a method of producing the model.

BACKGROUND ART

[0002] Tooth models are mainly used for dental trainings of dental
treatment, and tooth models suitable to various kinds of dental trainings
are increasingly in demand as tooth models are becoming popular in the
world. A type of dental trainings includes a dental training for removing
tartar from teeth.

[0003] Conventionally, some tooth models used for training for removing
tartar are produced by attaching a material equivalent to tartar to a
surface of a tooth model, (Patent Documents 1 and 2 are referred to). A
user is allowed to carry out training for removing tartar from a surface
of a tooth model by scraping off attachment using a scaler and the like.

[0006] However, since a material equivalent to tartar is manually attached
to the conventional tooth model, it is very difficult to prevent
variation in how the material is attached (particularly, a place to be
attached and the attaching force) among a plurality of tooth models.
Consequently, it has not been possible to keep a skill obtained through
the training consistent or evenly evaluate the result of the training of
the user.

[0007] In consideration of the situation described above, the object of
the present invention is to provide a tooth model that allows forming of
a part equivalent to tartar uniformly, and to provide a method of
producing the tooth model.

Means for Solving the Problems

[0008] The inventor, and the concerned personnel, of present invention
present the following invention for solving the aforementioned problems.

[0009] (1) A tooth model used for a dental training, the tooth model
including:

[0010] a main body that is formed in imitation of a form of a tooth and
includes a tooth crown and a tooth root; and

[0011] a protrusion protruding from a surface of the main body seamlessly,
wherein

[0012] the main body and the protrusion are made of the same material.

[0013] (2) The tooth model noted in (1), in which the protrusion has a
size of 0.3 mm to 0.7 mm, both ends inclusive, in a plan view.

[0014] (3) The tooth model noted in (1) or (2), in which the protrusion
has an edge portion on a tooth root-side of the protrusion having a form
expanded toward the tooth root side in a plan view.

[0015] (4) The tooth model noted in (3), in which the protrusion has an
edge portion on the tooth root-side having a partial form of a circular
arc or elliptical circular arc in a plan view.

[0016] (5) The tooth model noted in any of (1) through (4), in which the
protrusion has a maximum height of 0.15 mm to 0.35 mm, both ends
inclusive.

[0017] (6) The tooth model noted in any of (1) through (5), in which the
protrusion has a form having no sharp-angle corner in a cross-sectional
view that is perpendicular to a tooth axis of the tooth model.

[0018] (7) The tooth model noted in (6), in which the protrusion has a
partial form of a circular arc or elliptical circular arc in a
cross-sectional view that is perpendicular to the tooth axis.

[0019] (8) The tooth model noted in any of (1) through (7), in which the
material provides a Brinell hardness of 20 to 30, both ends inclusive,
and provides a flexural strength of 700 kgf/cm2 to 1000
kgf/cm2, both ends inclusive.

[0020] (9) The tooth model noted in any of (1) through (8), in which the
dental training is that for removing tartar.

[0021] (10) A method of producing a tooth model used for a dental
training, the method

[0022] that uses an elastically deformable molding die having a concave
part formed substantially symmetrical to a form of the tooth model, with
the concave part provided with a small dent on a surface of the concave
part and includes the steps of:

[0023] supplying the concave part with a material fluid that is a raw
material for the tooth model;

[0024] causing the material fluid to solidify in the concave part to form
the tooth model having a protrusion in a form substantially symmetrical
to the miniature dent on a surface of the tooth model; and

[0025] extracting the tooth model from the concave part.

Effects of the Invention

[0026] The present invention is configured so that the protrusion
corresponding to tartar is made of the same material as the main body
seamlessly between the protrusion and the main body, and thereby an
integral molding with the main body is enabled. Therefore, it is possible
to repeatedly use a common molding die, enabling uniform forming of the
part corresponding to tartar.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027]FIG. 1 is an oblique view diagram showing a usage mode of a tooth
model according to an embodiment of the present invention;

[0028]FIG. 2 is a cross-sectional diagram of FIG. 1 along the line II-II;

[0029]FIG. 3 is a diagram showing an enlargement of the a portion shown
in FIG. 2;

[0030]FIG. 4 is a plan view diagram of a protrusion shown in FIG. 2 and
the vicinity of the protrusion;

[0031] FIG. 5 is a cross-sectional diagram of FIG. 4 along the line V-V;
and

[0032] FIGS. 6(A)-(C) are diagrams showing the process of producing the
tooth model according to the aforementioned embodiment.

EXPLANATION OF REFERENCE NUMERALS

[0033] 1: jaw model

[0034] 10: tooth model

[0035] 11: tooth crown

[0036] 12: tooth root

[0037] 121: tooth root-side surface

[0038] 123:
tooth crown-side surface

[0039] 13: protrusion

[0040] 131: apex portion

[0041] 133, 135: end portion

[0042] 134, 136: edge portion

[0043] 20:
tooth pedestal

[0044] 21: insertion hole

[0045] 30: model gum

[0046] 50:
molding die

[0047] 53: cavity part

[0048] 531: miniature dent

PREFERRED MODE FOR CARRYING OUT THE INVENTION

[0049] The following is a description of an embodiment of the present
invention with reference to the accompanying drawings,

[0050]FIG. 1 is an oblique view diagram of a jaw model 1 that includes a
tooth model 10 according to an embodiment of the present invention; and
FIG. 2 is a cross-sectional diagram of FIG. 1 along the line II-II.

[0051] The jaw model includes the tooth model 10, a tooth pedestal 20, and
a model gum 30. The tooth model 10 is used for a dental training and
includes a tooth crown 11 and a tooth root 12. The tooth root 12 is
inserted into an insertion hole 21 arranged along a tooth column of the
tooth pedestal 20, and such tooth pedestal 20 is covered with the model
gum 30 so that the tooth model 10 is supported by the tooth pedestal 20.

[0052] The tooth crown 11 and the tooth root 12 are formed in imitation of
the form of a tooth, and they constitute a main body of the tooth model
10. The tooth model 10 according to the present invention includes a
protrusion 13 that protrudes from a surface of the main body seamlessly.
Such protrusion 13 can be formed integrally with the main body, and
therefore a part corresponding to tartar can be formed uniformly by
repeatedly using a common molding die (described in detail later). It is
appreciated that so long as a tooth model is provided with the protrusion
13, such a tooth model in which another member is further attached onto
the protrusion 13 (N.B.: there will be a seam intervening between the
other member and the main body) will be included in the spirit and scope
of the present invention.

[0053]FIG. 3 is a diagram showing an enlargement of the a portion shown
in FIG. 2. FIG. 4 is a plan view diagram of a protrusion shown in FIG. 2
and the vicinity of the protrusion. FIG. 5 is a cross-sectional diagram
of FIG. 4 along the line V-V.

[0054] The protrusion 13 of the present embodiment is disposed in both the
tooth crown 11 and the tooth root 12 but it is not limited thereto. An
alternative configuration may be such that the protrusion 13 is disposed
in only the tooth crown 11 or tooth root 12. The number of the protrusion
13 is not limited. Rather, the number may be singular or plural. Further,
the form and the size of the protrusion 13 are not particularly limited.
Rather, the protrusion may be a sphere, cuboid, cube, or indefinite
shape, of any given size. In a case where a plurality of the protrusions
13 is formed, the form and the size of the protrusions 13 are preferred
to be mutually and substantially the same. Alternatively, the form and
size may be mutually different.

[0055] However, the protrusion 13 desirably has a size of 0.3 mm or
larger, more desirably 0.35 mm or larger, or most preferably 0.4 mm or
larger, in a plan view. With such a configuration, when the protrusion 13
is removed with a removal instrument (e.g., various kinds of scalers) in
dental training, an appropriate level of force as in actually tartar
removal is required, and the user is provided with a similar feeling as
in actual tartar removal, and therefore it is possible to further improve
a result of the dental training. Further, the protrusion 13 desirably has
a size of 0.7 mm or smaller, more desirably 0.65 mm or smaller, or most
preferably 0.6 mm or smaller, in a plan in contact with the protrusion 13
in a dental training, a feeling conveyed to a person holding the removal
instrument is closer to the case of actually contacting tartar, and
therefore it is possible to further improve a result of the dental
training.

[0056] It is noted that the plan view is defined as a visual field when
the protrusion is viewed from a direction orthogonal to a surface of the
main body located near the protrusion. The size is defined as a size in
relation to all directions going through the center of gravity of the
protrusion in a plan view. For example, the size of 0.3 ram to 0.7 mm
both ends inclusive, means that the minimum value (for example, a shorter
diameter S in a case where a plan view of the protrusion 13 is an
ellipse) of the size in relation to all directions is 0.3 mm or larger,
and that the maximum value (for example, a larger diameter L in the case
where the plan view of the protrusion 13 is the ellipse) is 0.7 mm or
smaller. Further, in a case where there is a plurality of protrusions,
the size means the average value of the sizes of all of them.

[0057] Incidentally, the majority of tartar removal instruments generally
has a tip of a partiaz circular arc and is moved from a tooth root side
to a tooth crown side to remove tartar. Accordingly, the protrusion 13 is
preferably configured so that an edge portion 134 on the tooth root side
(i.e., the lower side in FIGS. 2 and 4) has a form expanded toward the
tooth root side in a plan view. With this configuration, when a dental
training is carried out, the tartar removal instrument contacts the
protrusion 13 on a face or a plurality of points of the instrument,
giving the user a feeling similar to a feeling that the user obtains in
removing actual tartar. Further, with the configuration, applied force
from the tartar removal instrument is evenly exerted to the entirety of
the protrusion 13, and therefore, removal of the protrusion 13 requires
an appropriate magnitude of force similar to removing actual tartar.

[0058] The form expanded toward the tooth root side is not particularly
limited, and it may rather be configured by a straight line and/or a
curve. While a partial form of a circular arc or elliptical circular arc
is preferable from the standpoint of easily obtaining the above described
effect, such a configuration is not particularly limited, and rather the
sectional form may be formed by a polygon (i.e., triangle or higher
polygonal), a curve, or a combination thereof.

[0059] Now returning to FIG. 3, the protrusion 13 desirably has a maximum
height H of 0.15 mm or larger, more desirably 0.175 mm or larger, or most
desirably 0.20 mm or larger. This configuration makes it possible to
prevent the user from letting a tartar removal instrument from going over
the protrusion 13 without sensing it, thereby proving the user with a
feeling similar to a feeling which the user obtains when removing actual
tartar. Further, the protrusion 13 desirably has a maximum height of 0.35
mm or smaller, more desirably 0.325 mm or smaller, or most desirably 0.30
mm or smaller. This configuration makes it possible to prevent the
protrusion 13 from getting caught in a miniature dent 531 (described
later) of a molding die when the tooth model 10 is extracted from the
molding die, thereby facilitating the extract of the tooth model 10. In a
case where there is a plurality of protrusions, the maximum height is
represented by the average value of the maximum heights of all of the
protrusions.

[0060] The maximum height H of the protrusion 13 is defined as the maximum
value (i.e., the distance between an apex portion 131 and a virtual plane
I1 as shown in FIG. 3) of a height from a plane (i.e., the virtual
plane I1 shown in FIG. 3) produced by extending a tooth root-side
surface 121 that is located on the tooth root side, of the surface of the
main body in the surrounding of the protrusion 13. That is, the maximum
height H of the protrusion 13 means a height required for the tartar
removal instrument to climb over the protrusion 13 after moving it from
the tooth root side to the tooth crown side to come in contact with the
end portion 133 of the protrusion 13 on the tooth root side. In many
cases, while the maximum height H is the same or approximately the same
as the maximum value of a height from a plane (i.e., a virtual plane
I2 shown in FIG. 3) produced by extending a tooth crown-side surface
123 located on the tooth crown side, of the surface of the main body in
the surrounding of the protrusion 13, there may be a possibility of the
aforementioned two heights being different from each other in a case
where a surface of the main body in the surrounding of the protrusion 13
is greatly curved or distorted.

[0061] As shown in FIG. 5, the protrusion 13 preferably has an edge
portion 136 formed to have no sharp-angle corner in a cross-sectional
view orthogonal to the tooth axis, or more preferably to have a partial
form of a circular arc or elliptical circular arc. Such a configuration
prevents the protrusion 13 from getting caught in the miniature dent 531
(described later) of the molding die when the tooth model 10 is extracted
therefrom, thereby facilitating the extraction of the tooth model 10. The
partial form, however, may be constituted by a straight line, any given
curve, or a combination thereof. It is appreciated that the sharp-angle
corner means a corner of an angle of 90 degrees or smaller.

[0062] A material constituting the protrusion 13 and the main body may be
any given material provided that it is usable as a material for a tooth
model. An exemplary material is an epoxy resin. However, from the
standpoint of obtaining a higher training effect with the protrusion 13
having a form and size as described above, a preferable material has a
Brinell hardness of 20 to 30, both ends inclusive, and a flexural
strength of 700 kgf/cm2 to 1000 kgf/cm2, both ends inclusive.
It is noted that the Brinell hardness is measured in compliance with
Japanese Industrial Standard (JIS) Z 2243 and that the flexural strength
is measured in compliance with JIS K6911. Such a material will be
appropriately selected from among the aforementioned typical materials.

[0063] The tooth model 10 described above is used suitably for training of
removing tartar. That is, in the state of the tooth model 10 being
supported by the tooth pedestal 20, a tartar removal instrument is
operated to scrape the protrusion 13 off the tooth model 10 in a method
similar to actual removal of tartar. The tooth model 10 according to the
present invention allows an integrated forming, making it possible to
form the protrusion 13 uniformly by repeatedly using a common molding
die. This makes it possible to keep a skill that is obtained through the
training consistent, and uniformly evaluate a result of training for the
users. It is noted that the tooth model 10 may be used for purposes other
than training for tartar removal.

[0064] FIGS. 6(A)-(C) are diagrams showing the process of producing the
tooth model 10, Next a description of a method of producing the tooth
model with reference to FIGS. 6(A)-(C).

[0065] The method according to the present invention uses an elastically
deformable molding die 50 that includes a cavity part 53 having a form
substantially symmetric to the form of the tooth model 10 and in which a
miniature dent 531 is disposed in a surface of the cavity part 53 (FIG. 6
(A)). A material for the molding die 50 may be an elastic material which
is not affected by the material of the tooth model 10 and, for example, a
silicone resin. It is noted that the molding die 50 may be produced by a
typical method.

[0066] The cavity part 53 of the aforementioned molding die 50 is supplied
with a material fluid that is a raw material for the tooth model 10 (FIG.
6 (B)), and the material fluid is solidified in the cavity part 53 by
cooling and the like. This process forms the tooth model 10 having on its
surface the protrusion 13 of a form substantially symmetrical to the
miniature dent 531 (FIG. 6 (C)).

[0067] Then, the tooth model 10 is extracted from the cavity part 53. The
method of extraction is not limited. For example, the molding die 50 may
be divided on a plane passing through the center of the cavity part 53.
In this event, although the protrusion 13 may possibly get caught in the
cavity part 53 (in many cases, it is related to a circumferential
direction of the tooth model 10), the protrusion 13 can get out of the
cavity part 53 as a result of the molding die 50 being elastically
deformed. If the maximum height of the protrusion 13 (or the maximum
depth of the miniature dent 531) is within the above described range, or
if the protrusion 13 (or the miniature dent 531) has a form of having no
corner in a cross-sectional view orthogonal to the tooth axis of the
tooth model 10, the protrusion 13 can more easily get out of the cavity
part 53.

[0068] Such molding die 50 is repeatedly used to enable mass production of
the tooth models on each of which the protrusion 13 is formed uniformly.

[0069] The present invention is in no way limited by the embodiment
described above. Any modification, improvement, and the like, within the
scope of realizing the object of the present invention are included
therein.

EXAMPLES

[0070] Tooth models (with Brinell hardness of 25, and flexural strength of
899 kgf/cm2) were produced by: using three kinds of molding dies
having 24 pieces of semi-circular miniature dents of respective diameters
of 0.3 mm, 0.5 mm or 0.7 mm; and using an epoxy resin as raw material.
Seven panelists each using an ultrasonic scaler, a sickle scaler and a
curette scaler, respectively, for the three kinds of produced tooth
models were subjected to dental trainings for removing tartar. After the
dental training, each panelist evaluated for items shown in Table 1.
Evaluation points are as follows: